Internal-combustion engine.



F.'M. STANTON. INTERNAL COMBUSTION ENGINE.

APPLICATION FILED NOV- 6, I914.

mu I Patented July 24,1917.

2 SHEETS-SHEET 1. 1

mmgmd F. M STANTON.

INTERNAL COMBUSTION ENGINE.

APPLICATION man NOV. 6. 1914. v

' Patented July 24, 1917.

2 SHEEIS-SHEET 2.

. M d v jwm glwuen rom I FRANK M. STANTON, 0F PORTSMOUTH, NEW HAMPSHIRE.

INTERNAL-COMBUSTION ENGINE.

Application filed November 6, 1914.

To all whom it may concern:

Be it known that I, FRANK M. STANTON, a citizen of the United States, residing at Portsmouth, in the county of Rockingham and State of New Hampshire, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

This invention relates to internal combustion engines of the two-cycle variety which commonly designates that form of engine in which ignition of the explosive fluid takes place once to every revolution of the crank shaft.

As a particular object, it is contemplated by this invention to provide a combustion engine of the type mentioned which shall combine the well known advantages of this type with means for obviating admitted disadvantages such as the necessity for the use of a pump and the impossibility of completely scavenging the cylinder of the products of one combustion before introducing thereinto the next charge of motive fluid.

A further object and one more specific is the provision for conjunctive use with the main piston, of a follow piston to which is intrusted the duty of scavenging the cylinder and simultaneously drawing in the new charge of explosive fluid, this follow piston being automatically actuated by a cam which will serve to lock it in position at the moment of ignition at which time it serves to form the head of the explosion chamber.

It is a still further and likewise a specific object to provide inlet valves in the follow piston through which the mixture is admitted into the cylinder on the lower side of the piston after having previously been drawn thereinto on the upper side of the piston and to also provide springs for these valves which will readily equalize the pressure of the gas on both sides of the piston immediately before the moment of ignition.

The above and additional objects which will become apparent as this explanatory description proceeds, are accomplished by such means as are illustrated in the accompanying drawings, described in the following specification and then more particularly pointed out in the claim which is appended hereto and forms a part of this application.

With reference to the drawings, wherein there is illustrated the preferred embodiment of this invention as it is reduced to practice and throughout the several views Specification of Letters Patent.

Patented July 2 1, 1917..

Serial No. 870,648.

in which like characters of reference designate similar parts:

Figure 1 illustrates a vertical section taken centrally through one of the embodiments of an engine such as is comprehended by this invention,

Fig. 2 is an end elevational view of the matter shown in Fig. 1, parts being broken away, and Fig. 3 is a fragmentary sectional view taken through the novel follow piston to be disclosed hereinafter.

Referring now to the drawings, and more particularly for the present to Fig. 1, the numeral 5 designates a cylinder casting the lower portion of which is cylindrically enlarged as at 6, to permit the crank casing 7 to be secured thereto as indicated by the joints 8 in transverse central alinement therewith, this casing 7 being apertured to receive the engine shaft 9 rotatably mounted in suitable bearings 10 in any approved manner. A crank 11 is carried by the central portion of the drive shaft 9 and a fly wheel 12 is suitably keyed as indicated at 13 to one extremity thereof.

The upper portion of the cylinder casting 5 is formed with the cylinder portion 14 adapted to be surrounded by the customary jacket 15 which is spaced from the former to provide the water cooling space 16. The cylinder 14 is provided with a closure at its upper extremity consisting of a head 17 which is suitably recessed as designated by the numeral 18 to provide for the movement of the inlet valve 19 having the spring pressed stem 20 reciprocable through a usual boss formed in the cylinder head. An inlet duct 21 is provided through the head 17 and in communication with the recess 18 as intermittently determined by the movement of the valve 19.

A piston 22 is provided for reciprocation within the cylinder 14 under the impulsion of exploded charges of the motive fluid, such piston being of any usual construction and provided with connections 28 to the crank 11. lowermost movement of this piston 22 enables the latter to just uncover an exhaust port 24 formed through the cylinder walls and water jacket 14 and 15 as shown in Fig. 2.

It now remains to describe the particular construction of what is termed by this invention the follow piston whereby the par It should be noted that the limit of I 17 and ticular objects of the former are best accomplished. The piston head of this mechanism is of the necessary diameter to fit within the cylinder 14 and is denoted by the numeral 25 and. provided as shown particularly in Fig. 3 with a pair of vertically reciprocable valves 26 seating in the underface of the piston 25 and provided with stems 27 carrying heads 28 against which there act the resilient means 29 expansible to normally close the valves which determine intermittent communication between the portions of the cylinder 14 separated by this piston head by means of passageways 30, the use of which will be hereinafter more fully set forth.

A piston rod 31 mounts the described follow piston at one extremity and is slidable in suitable bearings 32 lining a vertical aperture formed in the central enlarged portion 33 of the head 17, leakage at this point being prevented by the removable stuiiing box 34 through which the opposite extremity of the rod 31 projects to make connections 35 with. the saddle 36. Connected to the other portion of this saddle piece and in a similar manner is the push rod 37 reciprocable through guides 38 and 39 formed re spectively integral with the cylinder head the crank casing 7 The lower portion of this push rod is provided with an angular extension 40 which bears at its extremity the integral cam tappet 41 adapted to be operated by means of a cam 42 rigidly connected to the crank shaft 9 and of the shape particularly illustrated in Fig. 2. Expansible resilient means surround the rod 37 and are interposed between the upper guide 38 and the lower extension 40 in order to normally maintain the rod, and consequently the piston 25 in that position particularly shown in Fig. 1 unless otherwise actuated by means of the cam42. Any suitable ineans of igniting the compressed charges within the cylinder 14 may of course be adopted although as at present illustrated a spark plug 43 of any desirable type is engaged through the cylinder and acket walls at the point at which the explosion chamber is formed by the conjunctive action of the main and follow pistons 22 and 25.

The operation of the enginedisclosed in the foregoing may be readily understood from a consideration of the fact that Fig. 1 illustrates the completion of the scavenging movement, the explosion having occurred just previously. Continued rotation of the crank shaft 9 which is assured by the inertia of the fly wheel 12 starts of course the piston 22 upon its upward movement covering the, exhaust port 24 and simultaneously starts the follow piston in the same direction due to the action of the cam upon the tappet 41 and push rod 37, against the action of the push rod resilient means. The previous downward movement of this piston which drove the products of the preceding combustion outwardly through the exhaust port 24 also served to create a partial vacuum in the upper portion of t 1e cylinder 14, causing an infiux of the explosive vapor through the inlet valve 19 due to the tendency to equalize pressures on both sides of the said valve. The upward motion of the follow piston 25 compresses the admitted charge to such an extent that the light springs controlling the yalves 26 in the piston head are overcome and permit the charge to be transferred to the underside of the piston 25 against the lower face of which the explosive charge is then compressed by the upward motion of the main piston 22. Conside'ring'that the follow piston has reached its upward limit of movement as determined bythe contact between the arcuate surface of the cam 22 and the tappet 41, it willbe apparent that i it is maintained in such upward position for approximately a half revolution due to the substantially semicircular shape of the cam which thu locks the pistonin position as the head of the combustion chamber for aninterval sufficient to permit the sparking means 43 to be actuated in igniting the com pressed explosive charge and to permit the piston 22 to nearly reach its lower limit of movement so that the exhaust port 24 is un covered. The release of the follow piston ig' almost instantaneous and serves to scavenge the cylinder and to draw in a succeeding charge of the motive fluid at one rush after 0 which. the operation of the engine goes on as before.

It will be apparent from the foregoing that with the admitted lightness and balance of operation to be found in the two-cycle en- 5 glue, that this invention has also obviated such disadvantages as the necessity for proriding a large fly wheel in order to produce an even rotation of the crank shaft on alter- 1 nate revolutions of engines of the four-cycle type and the impossibility hitherto met with of providing for the complete removal of the products of one combustion before the occurrence of the following explosion which has always heretofore resulted in a vitiating of the power of'said following explosions. The previously presented objects may accordingly be said to be accomplished by the means disclosed in the foregoing and provided by this invention, which clearly possesses the advantages and desirability set forth in such objects.

What is claimed is: in a two-cycle combustion engine, the combination of a cylinder, a working piston within said cylinder for actuating a crank shaft, a following piston within said cyllnden a piston rod. connected to the latter piston and passing through the head of the cylinder, a saddle piece fixed oncthe s outer end of said piston rod and projecting beyond the cylinder, a rod depending from said saddle piece and having a head on its lower end, guide means for the upper end of said rod and for the head of its lower end, an extension from the latter head outwardly through the guide means and longitudinally movable in a slot therein, a shoe projecting in opposite directions from said extension across the axis of the crank shaft, a cam below said shoe for acting thereon to push said rod and to positively force the followin piston to the explosion end of the cylinc er, resilient means for returning the rod and following piston as the cam rotates, and inwardly opening Valves in the following piston.

In testimony whereof I aflix my signature in presence of two witnesses.

FRANK M. STANTON.

Witnesses:

CONSTANCE Lowe, HAROLD M. SMITH.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

